Systematical Notes. 13 



The fin^t is essentially the same as Milne Edwards' fourth char- 

 acteristic but is more vaguely expressed. The second has, in my opi- 

 nion, no value, because almost all the Hyperids I have studied have the 

 power of doubling up the urus under the body, though this power is 

 not equally developed in the different genera. The third characteristic is 

 utterly artificial, and the use of it would lead to the separation of closely 

 related genera, and would place them in different families as for instance 

 Euthemisto among the Fhronimidœ instead of close to Hyperia. 



Spence Bate in 1862 followed Dana as to the distinction of Hy- 

 peridce and Phronimidœ from the other Hyperids, but for the division of 

 these latter into three families Flatyncelidœ, Phorcidœ and Oxycephalidœ, 

 he used the following characteristics. 



1. The head rounded, — or long, anteriorly produced. 



2. The eyes occupying the whole head — or only a part of it. 



3. The fifth pair of perasopoda with the femur largely developed, — 



or imperfectly developed. 

 The ßrst and second characteristics are not valuable for distinguish- 

 ing subtribes and scarcely constant as family-characteristics, while the 

 third is a purely generic characteristic. 



C. Claus in 1879 included under the name y)Platyscelidem> the fol- 

 lowing five families 1. Typhidce, 2. Scelidce, 3. Pronoidœ, 4. Lycceidce^ 

 and 5. Oxcyephalidce^ and used the following /a??i27y-characteristics. 



1. The body broad and short, — or more or less compressed, elongated. 



2. The urus able to be doubled up, — or without this power. 



3. The femora of the fifth and sixth pairs of perseopoda largely de- 



veloped, forming covers for the underside of body, — or the 

 femora elongated and narrowed. 



4. The urus very short, — or elongated. 



6. The mouth-organs broad and short, — or elongated and narrow. 

 The first characteristic I have already said is too vague and, in 

 my opinion, only of a specific value, for if you compare for instance the 

 female of Hyperia Latreillei with the female of Eutyphis ovoides, we find 

 the breadth of the body to be almost the same, and the body often not 

 more depressed in Eutyphis than in Hyperia. Also among the Lycœidœ 

 there are species almost fully as broad as a Dithynis or an Amphithyrus. 

 The second is, as I have already observed when discussing the familj'- 



